Theoretical investigation of rotational rainbow structures in X--Na/sub 2/ collisions using CI potential surfaces. III. Rigid-rotor X = Ne scattering

Journal Article · Fri Jan 15 04:00:00 EST 1982 · J. Chem. Phys.; (United States)

OSTI ID:5796297

Schinke, R; Mueller, W; Meyer, W

A thorough investigation of rotational rainbow structures in differential cross sections for the prototypical Ne--Na/sub 2/ system is presented. The scattering calculations are performed using an accurate CI potential energy surface, which includes electron correlation effects for the bond orbital of Na/sub 2/ and the L-shell orbitals of Ne together with the dispersion attraction between the two subsystems using the method of self-consistent electron pairs (SCEP). The surface is dominantly repulsive and highly anisotropic. A very shallow van der Waals minimum of about 0.3 meV is obtained at large internuclear distances. Coupled states and infinite-order-sudden differential cross sections are compared for a wide range of collision energies which allows for a critical test of the energy-sudden condition. The applicability of the centrifugal sudden approximation for Ne--Na/sub 2/ is also discussed. In particular, we investigate the dependence of the rotational rainbow structures on collision energy and initial rotational state. The positions of the primary rotational rainbows obtained with the CI and the corresponding Hartree--Fock surface are compared to experimental results. We find satisfactory agreement for the CI surface but considerable deviations if the Hartree--Fock surface is used. Finally, we compare the scattering results for Ne--Na/sub 2/ with those for He--Na/sub 2/ and conclude that at low energies (E< or approx. =100 meV) the drastic differences are mainly due to the different masses rather than the potential energy surfaces.

• Research Organization: Max-Planck-Institut fuer Stroemungsforschung, 3400 Goettingen, West Germany
• OSTI ID: 5796297
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 76:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular &amp; Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
COLLISIONS
CONFIGURATION INTERACTION
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DIMERS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FLUIDS
GASES
METALS
MOLECULE COLLISIONS
NEON
NONMETALS
RARE GASES
ROTATIONAL STATES
SODIUM
SUDDEN APPROXIMATION